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A novel reconfigurable 7R linkage with Multifurcation

Research output: Chapter in Book/Report/Conference proceedingChapter

Ketao Zhang, Andreas Müller, Jian Dai

Original languageEnglish
Title of host publicationMechanisms and Machine Science
PublisherKluwer Academic Publishers (Kluwer Academic Publishers Group)
Number of pages11
Publication statusPublished - 2016

Publication series

NameMechanisms and Machine Science
ISSN (Print)22110984
ISSN (Electronic)22110992

King's Authors


This paper investigates constraint singularity induced multifurcation of a novel 7R (R for revolute joint) linkage. Kinematic structure of the 7R linkage is described first for the purpose of geometric analysis. According to geometric properties of the kinematic structure, D-H parameters and kinematics equations in dual quaternion are derived subsequently. The study further explores analytical form of mechanism constraint-screw systems corresponding to distinct motion branches reconfigured from the 7R linkage based on reciprocity in screw theory. The constraint analysis reveals inherent properties of motion branch changes induced by constraints variation and geometric restriction of joints in these motion branches. This leads to identification of multifurcation of the reconfigurable 7R linkage, meaning motion-branch transitions between the non-overconstrained 7R linkage and overconstrained 6R and 4R mechanisms.

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